Press-guard



E. w. 25H.

PRESS GUARD.

-APPL,ICAT| 0N HLED APR.19. Q16. 1

Patented June 3, 1919.

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APPLICATION FILED APR. 29', I916.

Patented June 3,1919.

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E. W. ZEH.

PRESS GUARD;

APPLICATION FILQD APR. 29. 1916 1 305 763, Patented June 3,1919. 9 j 4 SHEET$' $HEET 3- INVENTOI? WITNESSES:

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EDMUND W. ZEH, OF NEWARK, NEW JERSEY.

PRESS-GUARD.

Specification of Letters Patent.

Patented June 3, 1919.

Application filed. April 29, 1916. Serial N 0. 94,284.

To all whom it may concern:

Be it known that I, EDMUND W. ZEH, a citizen of the United States, and a resident of Newark, in the county of Essex and State of New Jersey, have invented certain Improvements in Press-Guards, of which the following is a specification.

This invention relates more particularly to means for preventing a press from operating to close the dies together before the operator has removed his hand from between the dies, so as to insure safety and avoid accidents.

The objects of the invention are to provide an improved device of this character which will operate easily and positively, without unduly long movements or extra exertion; to necessitate the complete removal of the operators hands from the dies before the clutch can be thrown in; to positively lock the clutch-operating means until the guard is in protecting position; to unlock the clutch-operating means only by completely closing the guard; to provide a'guard which will lie close to the die, so that no long reach by the operator is required; to enable the guard to normally lie below the dies out of the way and move upward into protecting position so that it does not come so much into the line of vision of the operator;

to provide a guard adapted to various.

sizes and widths of presses; to secure looking mechanism which prevents the press from repeating even if the. clutchlpin or throw-out is worn; to enable the press to be operated in its usual manner, when the guard is applied; to provide a guard which will not obstruct or interfere with the use of the press for all purposes; to secure a neat and attractive appearance; to secure simplic- .ity of construction and operation, and to obtain other advantages and results as may be brought out in the following description.

Referring to the accompanying drawings,

in which like numerals of reference indicate the same parts throughout the several views, Figure 1 is a perspective view of a power press to which my invention has been applied;

Fig. 2 is a side elevation of the upper pornearits free end riding tion of said press with certain partsbroken y r Fig. 3 is a section through the clutch on line 33 of Fig. 2;

Fig. dis a view of the clutch from beneath illustrating disengagement of the same;

Figs. 5 and 6 are views similar to Fig. 2 showing the clutch-operating means in clifferent positions, and

,Figs. 7 and 8 are front views of the guard and rail showing the former in open and in closed or protecting position, respectively.

In the specific embodiment of the invention illustrated in said drawings, the reference numeral 1 indicates a guard applied to a power press 2. Said press is shown as comprising a table 3 carrying a lower or stationary die 4 above which is mounted a movable die 5 in a suitable ram 6 adapted to be oper ated up and down by any means well-known in the art, such as a crank shaft 7 extending V from side to side of the press above the movable die. A driving pulley 8 is rotatably mounted on one end of said crank shaft 7 and operatively connected therewith by normally enter a pocket 12 in the hub of'the is driving pulley, so that the shaft will be rotated by the pulley. In order to retract said clutch pin, so as to stop the shaft from rotating, a lever 13, pivoted as at 14 to the side of the press, extends transversely of the shaft under the collar with its upper edge within a peripheral groove 15 in said collar. g

The clutch pin 10 has a transverse shoulder, preferably formed by grooving said clutch pin transversely as at 16 so that the groove will register with the groove 15in the collar when thepin is withdrawn from its pocket 12 or thrown out, the shoulder 17 formed by the wall of said groove away from the driving pulley 8 lying betweenthe sides of the slot in the collar when the pin is thrown into its pocket 12 by the spring 11.

The upper edge of the lever 13 can therefore lie in both the groove 15 in the collar and the slot 16 in the clutch pin when the two register, by virtue of said lever being normally,

swung upward by a spring 18, and to enable the end of the lever to slide the clutch p n 10 out of engagement with its pocket" 12111 the driving pulley, the end of the lever is beveled as at 19, see Fig. 4, to enter behind the shoulder 17 of the clutch pin as said clutch pin is brought around by rotation as indicated by the arrow in Fig. 2. It will thus be understood that the lever 13 normally holds the clutch thrown out so that the ram 6 is inactive.

According to the present invention I provide a treadle 20 for lowering said lever 13 when it is desired to secure a blow of the dies, and the depressive movement of this treadle first operates the guard 1 and then operates the lever 13. To this end I provide a casing 21, shown on one side of the machine near the back, which casing provides an interior vertical slideway 22, adjacent its wall 23 toward the front of the press, for a rearwardly facing rack 24 the upper end of which is connected by an upwardly extending rod 25 to the lever 13 forward of its pivot 14, whereby longitudinal movements of the rack will cause swinging of the lever in corresponding directions. A similar second rack 26 is slidably arranged adjacent the wall 27 of the casing 21 farthest from the front of the press, and is provided with teeth 28 facing the teeth of the other rack 24; between these two racks 24, 26, in mesh with both of them, is a floating pinion 29 rotatably carried by the upper end of a treadle rod 30 secured at its lower end to the treadle 20 in front of its fulcrum 31. so that depression of the treadle results in a' positive lowering of the pinion.

In normal or inactive position of the press, the racks 24, 26 are both in their uppermost positions, and locking means is provided for holding the elutclroperating rack 24 in such raised position and the press idle until the other rack 26 has been enti'relv lowered by downward travel of the pinion 29 caused by depressing the treadle.

I have shown such locking means as con sisting of an inclined transverse arm ordetent 32 pivoted near the bottom of the casing between the racks 24, 26 to swing in the plane thereof and so that one end 33 may underlie the clutch-operating rack 24 to prevent .u from lowering until that end of said detent is swung upward out of the way, while the other end 34 will always underlie the other rack 26. Said last-mentioned end 34 of'the detent preferably provides a seat 35 to be engaged by the rack 26 and obviously when said rack is lowered far enough to engage said seat it will swing the detent to be lowered also. By curving the end. 33 of the detent underlying the c L tclyoperat ing'rack 24 with the center of cu rvature at the pivot of the detent, it will be appreciated that said detent maybe swung up clear of said rack without raising it, and when the detent is so swung the rack is free to slide downward. A suitable spring 36 mounted in the base of the casing 21 forces ashoe 37 against the detent to normally hold it in position to lock the clutch-operating rack 24, said spring being adjustably held in place by a screw plug 38.

It will'be obvious that upon depressing the foot treadle 20 to start the press, the pinion 29 will be lowered, but as the clutche operating rack 24 is locked in stationary position, the pinion must turn in being lowered; this turning will slide the locking rack 26 downward until. it engages and swings the detent 32 to release it from the other orclutch-operating rack 34, the swing of said detent being limited by engagement of its lower end 34 with the bottom of the casing 21 as a stop, so that the locking rack 26 can be depressed no farther. The detent having been thus removed from the path of the clutch-operating rack 24, continued depression of. the treadle will cause the pinion 29 to be turned by the now stationary locking rack 26 and depress the clutch-operat ing rack 24, thereby throwing in the clutch. By operating a guard plate or the like by means of the lockingrack 26, so that as said The particular means herein .shown for operating a guard plate ,or the like from the locking rack 26, comprises a horizontally disposed shaft 40 mounted in suitable bearings 41 on the press frame and extending at the side of the press from the back toward the front. The locking rack 26 is provided with teeth 42 on the side thereof facing outwardly from the side of the press, and meshing with said teeth 42 is gearwheel 43 fast upon the said shaft 40. Obviously, as the locking rack 26 is moved up or down by the pinion 29, the gear-wheel43 will be rotated and consequently will rotate the shaft 40. On the end of said shaft at the front of the press is a bent lever 44 firmly secured to rotate therewith, and piv- V corresponding arm 47 of a similar bent lever 48 pivotally mounted at the opposite side of the press in a position corresponding to that of the driving bent lever 44. The other arms 49, 50, of said bent levers 44,, 48 are pivoted to a guard plate 51 which extends across thefront of the press, or to end eX tensions thereof, so that as they swing they raise or lower the guard. lVhen thepress is idle, or normally, the guard 51 lies with its top edge closely adjacent to the front edge of the table 30f the press, and at that time, as shown in Figs. 1 and 2 more especially, it is preferable that the guard-carrying arms 49, 50 of the bent levers 44, 48 extend downwardly at substantially 45 to a horizontal line, so that as the shaft740 is rotated said arms will at once begin to move upward and quickly raise the guard. 'Each. 'ofsaid bent levers has its. arms at about right angles to each other, as shown, and thus the operating arms 45, 47. which are connected by the rod 46 swing through 45.

on each side of the vertical and the other arms 49, 50 which carry the guard swing through 45 on each side ofthe horizontal.

The length of movement of the locking rack 26, together with the diameter of the gear wheel 43, are proportioned so that the shaft 40 is turned about 90, to swing the guard-carrying arms 49, 50 from 45 below horizontal to 45 above horizontal, and thus the guard plate 51 is raised enough to fully protect the operator. Abore the guard plate, close enough to be contiguous'thereto when said guard plate is entirely raised, is a rail 52 parallel to the upper edge of the guard plate, said rail being-provided with lateral extensions 53 having suitable eyes 54 for re- :ceiving bolts 55 which secure the rail to the frame or any stationary portion of the press.

Said rail is high enough so that the operator will naturally and conveniently insert his hands under the same when changing or ma "nipulating his work, and yet by constructing 7 said rail of wire or rod, no difficulty will be experienced in observing the work and it will not obstruct the operator. Obviously, in operation, as thefoot treadle 20 is lowered,

the guard plate 51 is raised, but if the op erators hands or any other obstruction remains between the guard plate and rail 53 it will be impossible to raise the guard plate its entire distance, which means that the. 7 locking rack 26 cannot be lowered far enough to trip'thedetent 32 and allow the clutch to connect the crankshaft 7 with the driving pulley 8.. However, as soon as the obstruction is removed, the guard plate is allowed torise through its full movement, and the locking rack 26 will then trip the detent and the clutch will be thrown in, causing a blow of the-press. 7

The guard plate 51may be of any suitable construction, although I have shown it of perforated sheet metal and curved upwardly inward toward the dies. Furthermore, it can be of any desired size, either in height or width, if connected to the bent lever arms 49, 50 by extensions which may be varied in length, the rail 53 being bent or changed to correspond. In the drawings, I have shown one such extension 56 employed to connect the guard plate to the supporting arm 49, said extension being sufiicient merelyto center the guard plate with respect to the press and the plate being of such length that it is pivoted directly at its other end to the arm 50. In order to secure a proper pivotal connection of the arms 49, 50 to the guard plate or extensions thereof, studs 57 have reduced ends 58 rotatably seated in sockets in said 7 arms parallel to the axes on which the arms turn, cotter pins 59 or the like holding said studs from escape. The guard plate is then secured direct to the head of one of said studs and the extension 56 is inserted in the head of the other stud, as shown. The ends of the connecting rod 46 are bent and rotatably inserted in sockets in the arms 45, 47, also. parallel to the axes on which the arms turn, as shown at 60, and are held by cotter pins 61 or the like.

hen. the foot treadle 20 is released its spring 62, see Fig. 1, raises it to normal position, thus tending to push the floating pinion 29 upward, see Fig. 6. The pinion, however, is in engagement at one of its edges with the guard-operating rack 26, movement of which must operate the guard and thus take place against considerable resistance; the pinion engages at its opposite edge the clutch-operating rack 22 which is impelled upward by the spring 18 which releases the clutch and therefore moves very easily, if indeed it does not actually draw upon the pinion.

matically returns under the clutch-operat ing rack.24 as soon as the guard-operating rack 26 starts upward.

Obviously detail modifications and changes may be made in 'manufacturing my improved press guard without departing from the spirit and scope of the invention and I do not wish to be understood as restricting myself except as required by the following Under these conditions" the guard-operatmg rack 26 will standstill,

claims when construed in the light of the prior art.

Having thus described the invention, what I claim is:

1. The combination with a press having a clutch and a guard, of two racks one for operating the clutch and the other for operating the guard, a pinion member adapted to transmit motion to both said racks, and means for causing said pinion member when moved in one direction to move the guardoperating rack until it stops and then move the clutch-operating rack.

2. The combination with a press having a clutch and a guard, of two racks one for operating the clutch and the other for operating the guard, a pinion member adapted to transmit motion to both said racks, and means for causing said pinion member when moved in one direction to move the guardoperating rack until it stops and then move the clutch-operating rack and when moved in the other direction to return both racks to initial position.

3. The combination with a press having a clutch and a guard, of two racks one for operating the clutch and the other'for operating the guard, a pinion member adapted to transmit motion to both said racks, and means for causing said pinion member when moved in one direction to move the guardoperating rack until it stops and then move the clutch-operating rack and when moved in the other direction to move the clutchoperating rack until it stops and then move the guard-operating rack.

4. The combination with a press having aclutch and a guard, of two racks one for operating the clutch and the other for operating the guard, a floating pinion engaging both said racks, means for moving said pinion longitudinally of the racks, andmeans for causing said pinion when moved in one direction to move the guard-operating rack until it stops and then move the clutch-operating rack.

5. The combination with a press having a clutch and a guard, of two racks one for operating the clutch and the'other for operating the guard, a pinion member adapted to transmit motion to. both said racks, a lock for the clutch-operating rack adapted to be released'by the guard-operating rack when moved 1n one direction, and means for causing the clutch-operating rack to slide first upon movement in the other direction.

(3. In a press, the combination with a clutch and a guard, of two racksone for operating said clutch and theother for operating said guard, a pinion between said racks engaging them at its opposite edges, means for moving the pinion longitudinally of said racks, means for causing one of the racks to slide first when the pinion moves in one direction and means for causing the mos-pea 8. In a press, i318 combination with a.

clutch and a guard, of two racks one for operating said clutch and the other for oper ating said guard," a pinion between said racks engaging thematits opposite edges, means for moving said pinion longitudinally ofsaid racks, a'spring normally sliding the clutch-operating rack to throw out the clutch,-and a lock positively holding said clutch-operating rack with the clutch thrown out'and adapted'to be released by the other rack when the guard ism-protecting posi-' tion.

9. In a' press, the combination with a clutch anda guard, of two racks one for operating said clutch and the otherfor operating said guard, a pinionbetween' said racks engaging them at'its opposite edges, means for moving'said'pinion' longitudinally of'said racks, a spring normally sliding the clutch-operating rack to throw out the clutch, and a detent pivoted-intermediate its ends to swing 'in' the plane of said racks and normallylying with oneend locking the clutch-operating rack and its other' end in the path of the other rack.

10. The combination with a ar'ess, of bent levers arranged at'thefront oi the press to swing in'a plane parallel thereto, a rod connecting corresponding arms of saidlevers in substantially parallel relation, a guard mounted'on the other two arms of saidlevers, and means for swinging'one' of said levers.

11. The combinationwith axpress, of substantially parallel arm's" extending in the same direction at the' front of'the press to swing in a plane parallel thereto, a guard pivoted to-the freeends of said arms and having for this purpose a longitudinal extension so that'the guard can be centered between thepoints of pivoting of said arms, and means for swinging said arms to raise and lower said guard. 7 '7 12. In a press, the combination with a clutch and'a guard, of two racks one for operating said clutch and the other for operating saidguard, a pinion between said racks, means for moving said pinion longitudinally of said racks, a lock'for' said clutch-operating rack adapted to be operated by the guard-operating rack when the pinion is moved in one direction, and means for causing the clutch-operating rack to slide first when the pinion is moved in the other direction.

13. In a press, the combination with a clutch and a guard, of two racks one for operating said clutch and the other for operating said guard, means normally holding the clutch thrown out and the said clutch Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

member at one limit of its range of movement, a look for holding said clutch member at said limit of its range of movement and adapted to be released by the guard, a pinion between said raoks engaging both of vthem, and means for moving said pinion back and forth.

EDMUND W. ZEI-I.

Washington, D. C. 

